1. Field of the Invention
This invention relates to a wiring unit housed in an electric connecting box mounted in a motor vehicle that is a moving body.
2. Description of the Related Art
The motor vehicle is generally provided with a variety of electronic appliances inclusive of lamps such as a head lamp, tale lamp, etc. motors such as a starter motor, a motor for an air conditioner, etc.
In order to supply power to the variety of electronic appliances, junction blocks are located at suitable position within the motor vehicle. The junction block is configured so that printed boards and wiring boards with elements such as bus bars are stacked and various electric circuit units such as a large number of fuses, relays, etc. are integrated on these wiring boards.
The junction block may includes a fuse, relay, bus bar, etc. so that it is called a fuse block, relay box, or generally an electric connecting box. In this specification, the above fuse block, relay box, junction block, etc, are referred to as the electric connecting box.
The electric connecting box includes a case and a wiring plate, etc. The case can be provided with electric components such as a relay, fuse, connector. A plurality of electric wires connected to the various electric appliances are led into the case. The wiring plate, when it is housed in the case, electrically connects the electric wires connected to the various electric appliances to terminals of the various electric components in a prescribed pattern.
As the above wiring plate, in order to facilitate the connection of the respective electric wires to the terminals of the electric components, a wiring unit 54 as shown in FIG. 8 as been proposed. The wiring unit as shown in FIG. 8 includes a plurality of boards 61 which are stacked successively, a plurality of terminals 62 and a plurality of connecting bars 63, The boards 61 each is made of an insulating material. The boards 61 each is formed as a square flat plate.
The boards 61 each includes a plurality of grooves 64, a plurality of concave portions 65 and a plurality of through-holes 66. The grooves 64 each is formed in concave from the surface of the board 61. The grooves 64 each extends in a longitudinal direction of the board 61. The respective grooves 64 are formed in parallel to one another.
The concave portions 65 each is formed in concave from the surface of the board 61. The concave portions 65 each is opened into the groove 64. The concave portions 65 are provided in parallel to one another in the longitudinal direction of the corresponding groove 64. The concave portions 65 each is formed in a square shape when viewed from above.
The through-holes 66 each passes through the portion located at the bottom of the corresponding concave portion 65. The through-holes 66 are located at the corresponding positions when the boards are stacked successively.
The terminals 62 each is made from a metallic sheet. The terminal 62 is composed of an electric contact portion 67 and an electric-wire connecting portion 68. The electric contact portion 67 is adapted to receive in the above connecting bar 63. When the connecting bar 63 is received in the electric contact portion 67, it produces elastic restitutive force that impedes the insertion of the connecting bar 63 so that the relative position of the connecting bar 63 to the electric contact portion 67 is maintained.
The electric-wire connecting portion 68 permits an electric wire (FIG. 9) to be arranged unidirectionally. The electric-wire connecting portion 68 includes a crimping segment 70 on which the electric wire 69 can be crimped and a pair of electric-wire holding segments 71 which are located at the positions where the electric wire 69 is sandwiched in the direction of arranging the electric wire 69.
The crimping segment 70 is provided with two pairs of press-fitting blades 72, which cut the coating of the electric wire 69 to come in contact with the core thereof. The electric wires each is provided with a pair of caulking pieces 73 between which the electric wire 69 with the coating is caulked. The caulking pieces 73 sandwiches the electric wire 69 therebetween so that the contact state of the press-fitting blades 72 of the crimping portion 70 and the core.
The electric contact portion 67 and the electric-wire connecting portion 68 are arranged at the positions where the electric wire 69 is not impeded. Specifically, in the direction of arranging the electric wire 69, the electric connecting portion 67 is arranged to intersect the electric-wire connecting portions 68.
The terminal 62 connects the electric wire 69 crimped on the crimping portion 70 or electric-wire connecting portion 68 and the connecting bar 63 inserted into the electric contact portion 67 to each other. The terminal 62 is attached to the board 61 in a state where the electric contact portion 67 is housed in the concave portion 65 and the electric connecting portion 68 is housed in the groove 64.
The connecting bar 63 is made of a conductive material. The connecting bar 63 is formed in a band shape. The connecting bar 63, when inserted into the hole 66 and the electric connecting portion 67 of the terminal 62, is electrically connected to the electric wire 69.
In the wiring unit having the configuration described above, the electric wires 69 connected to various electric appliances are arranged in the grooves 64. By stacking a plurality of boards 61 and optionally selecting the concave portions 65 and holes 66, the electric wires 69 each is electrically connected to the electric component such as the relay, fuse, connector, etc. according to a prescribed pattern.
In the wiring unit 54 shown in FIG. 8, in order to form the concave grooves 64 and the concave portions 65 in the boards 61, relatively complicated uneven spots must be formed on the surface of the board 61. Therefore, the molding die for molding the board 61 becomes also complicate in shape. This leads to rise in the production cost.
The terminal 62 is generally formed by bending a metallic plate. However, since the metallic plate must be bent at many points, the number of man-hours needed to manufacture the terminal 62 is increased. This further leads to a rise in the production cost.
In assembling of the wiring unit 54, the lead 69 must be crimped after the terminal 62 has been attached to each of the board 61. This increases the number of man-hours for assembling and hence leads to a rise in the production cost.
Further, the circuit configuration of the wiring unit 54 is constructed of the electric wire 69, terminal 62 and connecting bar 63 inserted in the electric contact portion 67. In this case, the electric wires 69 and terminals 62 are superposed on each other in a direction of stacking the boards 61. This increases the limitation to the circuit design and upsizes the wiring unit.
An object of this invention is to provide a wiring unit which can be minimized in production cost and size.
In order to attain the above object, in accordance with this invention, there is provided a wiring unit comprising:
a plurality of printed circuit boards on the surface of each of which a grid-like conductor pattern is formed, each having a plurality of through-holes passing through the conductor pattern, the printed circuit boards being successively stacked; and
a pin unit including a pin segment made of a conductive material and a conductor contact which protrudes outwardly therefrom, wherein the pin segment can be inserted into each the through-holes and is apart from the conductor pattern when it is inserted into the through-hole, and the conductor contact can be brought into contact with the conductor pattern.
In this configuration, by inserting the conductive pin into the through-hole of the printed circuit board, the conductor patterns of the printed circuit boards can be electrically connected to each other. Therefore, by selecting the through-hole into which the conductive pin is inserted, the conductor patterns can be connected to each other in accordance with a prescribed pattern. In this way, the relative simple configuration of the printed circuit board having a grid-like conductor pattern into which the through-holes are made can assure a desired electric connection, thereby reducing the number of man-hours required for the production of the components. Further, the mold for molding the printed circuit board can have a relatively simple, thereby suppressing rise in the production cost.
Further, the through-hole passes through the conductor pattern so that they are not displaced from each other, the increase in the size of the printed circuit board can be suppressed. The printed circuit board, which has a grid-like conductor pattern, can be further miniaturized. Therefore, the wiring unit itself can be miniaturized.
In a preferred embodiment, the conductor contact has a pair of spring segment segments which are attached to the outer wall of the pin, the spring segment segments being elastic in a direction of approaching/leaving the pin, the spring segments generating elastic restoring force to sandwich the printed circuit board therebetween when the conductor contact is inserted into the through-hole while one of them is brought into contact with the conductor pattern.
In this configuration, since one of the pair of spring segments of the conductor contact which can approach or leave each other is connected to the conductor pattern, an electric connection can be assured between the pin unit and the conductor pattern. Therefore, the conductor patterns can be electrically connected to each other more surely in accordance with a prescribed pattern.
In a preferred embodiment, the conductor pattern of the printed circuit board is partially removed to provide a recess in the conductor pattern. In this configuration, since the grid-like conductor pattern is partially recessed to provide conductor recesses, flexibility in the connecting pattern of the conductor pattern or a circuit pattern can be increased.
In a preferred embodiment, the conductor pattern has a first plurality of belt-like conductors arranged in parallel and a second plurality of belt-like conductors which are arranged in parallel and cross the first plurality of belt-like conductors; and
the through-holes are provided at crossing points where the first plurality of belt-like conductors and the second plurality of belt-like conductors cross each other.
In this configuration, the through-hole passes through the crossing point where the first belt-like conductor and second belt-like conductor of the conductor pattern cross each other. Therefore, by inserting the conductive pin into the through-hole, the conductor patterns can be electrically connected to each other surely in accordance with a desired pattern.
In a preferred embodiment, at least one of the plurality of printed circuit boards is provided with male tabs formed so that at least one of the first and the second belt-like conductors protrude outwardly from the edges of the printed circuit board. The male tabs are connectable to electric wires electrically connected to an electronic appliance. The belt-like conductors can be electrically connected to each other and the belt-like conductors can be electrically connected to the electronic appliance.
The above and other objects and features of this invention will be more apparent from the following description taken in conjunction with the accompanying drawings.